1. Field of the Invention
The invention relates to a basket for cleaning which holds semiconductor wafers cut by a wire saw and a method of cleaning semiconductor wafers using the same, in a cleaning step of removing away abrasive grains and grease components from the wafers.
2. Description of the Prior Art
Conventionally, semiconductor wafers which have been cut by a wire saw are arranged under a state where their peripheral portions are bonded to a slicing plate made of carbon or the like, and then transported to a cleaning bath while being hung from a lifter. The semiconductor wafers are cleaned in the cleaning bath so that abrasive grains and grease components are removed away from the wafers. Thereafter, the semiconductor wafers are finally caused to be separated from the slicing plate, by an alkaline cleaning fluid. The separated semiconductor wafers are piled up in the cleaning bath, and then picked up.
In order to align the crystal orientations of semiconductor wafers, the cutting work using a wire saw must be conducted while adjusting the cutting direction of a semiconductor ingot. Therefore, the end portions of the ingot are cut into an irregular shape, and a part of the irregular-shape portions surely drops off. During the cleaning for removing abrasive grains and grease components, sometimes, several semiconductor wafers slip off from the slicing plate. These slipping off semiconductor wafers or semiconductor pieces produce a problem in that they drop into the cleaning bath and crack to cause a trouble in a cleaning apparatus.
When the semiconductor wafers are separated from the slicing plate in the cleaning bath, the wafers lose the support and fall over like a file of dominoes. This produces a problem in that, when the semiconductor wafers are then to be transferred to a wafer carrier, the efficiency of the work of picking up wafers is poor.
The invention has been conducted in view of the problems discussed above.